Air Compressors - Help please...

[sailorman]

Hi Y'all,

I am planning a variation on the air recirculating ballast system, to be installed in a Robbe U-47. Here is the bare bones; A 12 inch bicycle inner tube laid into the hull in the saddle tank area connected to a compressor within the WTC.
Air will be moved into the tube to surface and sucked out to dive. The Robbe WTC is designed to be pressurized so I see no problems there.
What is a good choice of compressor? I plan to run her on 7.2 volt NIMH packs, so I am looking for a 6-12 volt unit with the lowest current draw possible. I have looked at several auto emergency units, but they seem to be built into the "box" in such a way as to preclude removal. Also the unit needs to be reverseable.
Any help here will be greatly appreceated,
Steve

[Guest]

Steve,
The 6V compressors (pumps), of

Steve,
The 6V compressors (pumps), of the type that are in automatic blood pressure machines, work well at 7.2V, also. I have a few left.
If you use the air from the WTC, the compressor does not have to reverse to "suck the air" out of the inner tube. The partial vacuum created in the WTC will do that. The air just has to be released by any simple valve. See the RCABS text article, under Documents, on my site; Art Broder's Models You may have to join the group (free) to see the Documents page.

[ron]

Steve,

Please take a look at

Steve,

Please take a look at Art Broder's membership page and Dave Welch's. There is also a photo spread on Tim Smalley's website
on dave's WTC for his Akula. Both of these systems use Art's mini air pump system. This seems to be exactly what you are
looking for.(www.rc-submarines.com) There is also a write up by Art, in I believe the Dec. 2003 SCR issue.

Ron

[Guest]

Ron, Steve, and others,
The RCABS

Ron, Steve, and others,
The RCABS article appeared in the March 2004 SCR, #56. It is titled "A Simple Ballast System" and is on page 50. If you need clarification or help, ask here, or e-mail me.

[dietzer]

Art,

I'm not sure the WTC

Art,

I'm not sure the WTC will hold enough air for Steve to fully inflate (and pressurize) a 12" bicycle inner tube. As I recall, your RCABS normally pumps up a couple of blood pressure cuff bladders, which I think hold considerably less air than a 12" inner tube does.

Also, I'm not sure how much pressure the blood pressure air pumps can generate. I would think you would want at least 15-20 lbs psi in the inner tube to inflate it. Can one of the little blood pressure air pumps handle that?

I'm guessing Steve might need a pressure vessel to hold enough air to inflate the inner tube.

Please note that I'm assuming that the 12" inner tube has not been shortened significantly...

Carl

[Guest]

Carl,
It shouldn't be a problem.

Carl,
It shouldn't be a problem. If there is enough room for the inner tube to fully inflate, it probably will. My "Alfa ballast bladder" video, on my web site, shows a child size bladder inflating. The pump also fully inflated an adult size bladder from a 15" by 3" WTC. See the video on the Documents page of my web site, referred to in my previous post above. This might get you to the page, My Webpage Documents



Edited By Art Broder on 1096952875